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I wish to establish a baseline for my AHI . So far I am not aware of any standard procedure on this topic . As a result, I am thinking along this line :

_Set the pressure of the CPAP machine @ say, 0.1 cm H2O ( i.e. to simulate the case breathing without the CPAP machine)
_Record the AHI readings for a few days
_Then use the average as my AHI baseline .

Is this logical ? Please comment.

_I am also wondering if there is a commercial device that measures the AHI ( i.e. independent of the CPAP machine ) .

The only device I know that is capable of registering apneas without a CPAP is an EEG. I think it would be far cheaper to pay for a sleep study. The sleep labs have all the toys that you're looking for.

The lowest pressure any CPAP machine can provide is 4.0 cm-H2O, so if you're determined to operate at low pressure to get an untreated AHI, that will be your starting point. The standard procedure to established a diagnostic AHI is to use either a home sleep study device or the best is a clinical polysomnograpy.

If you suspect you have obstructive sleep apnea, you are probably not wrong. A sure sign is when your wife or partner kicks you out of the bedroom for obnoxious snoring, and your own personal sense of fatigue, arousals, poor sleep quality, and in extreme cases falling asleep at work or while driving. A home sleep study can be obtained at reasonable cost from Supplier #30 and others. They will also provide diagnostic and prescription services if needed. My recommendation is that you use an auto CPAP machine, and just set it from 6.0 to 14.0 and see what the results are, then dial in the best therapy based on the data. Since you have a Resmed Airsense 10 Autoset, the machine will produce full data, and you can interpret the results from the free SleepyHead program (much easier to understand and better information than ResScan).

Another way.... and I know it's odd but you can often see how bad it is. Using a dim light, set a video recording device, i.e phone, camcorder, camera on record etc. Record yourself. When I did this I could easily see what was happening. I stopped breathing and then sucked air every minute. So, at least an ahi of 60. If it was 50 or 80, didn't matter. I had apnea. No question.

Later when I got my cpap machine I did set it to the lowest settings and Sleepyhead indicated the number of apneas I was having.
So, yes, in my experience I could without a doubt, diagnose myself with obstructive apnea.

Then again, all I needed to do was listen to my wife who long watched me do the same thing. I actually didn't have to do this other stuff.

(07-09-2018, 05:03 PM)DanGagner Wrote: Another way.... and I know it's odd but you can often see how bad it is. Using a dim light, set a video recording device, i.e phone, camcorder, camera on record etc. Record yourself. When I did this I could easily see what was happening. I stopped breathing and then sucked air every minute. So, at least an ahi of 60. If it was 50 or 80, didn't matter. I had apnea. No question.

Later when I got my cpap machine I did set it to the lowest settings and Sleepyhead indicated the number of apneas I was having.
So, yes, in my experience I could without a doubt, diagnose myself with obstructive apnea.

Then again, all I needed to do was listen to my wife who long watched me do the same thing. I actually didn't have to do this other stuff.

Conclusion: Listen to your wife. LOL
I like your approach. Seeing what struggling for air looks like is a powerful motivator for treatment.

Thanks everyone for commenting on various aspects of the AHI baseline question .

The lowest pressure I can set on my CPAP machine ( i.e. ResMed Airsense 10) is 4 cm H2O . So I have no choice but starting out with pressre set @ 4.0 .
Another factor got into the picture : mouth breathing inside the full face mask ! To resolve this issue , I used mouth tapping ( i.e. using 3 pieces of
medical bandage tape , and taped them vertically , a long one at the center line and 2 short ones at the corners of the mouth ) .

So far , this mouth tapping works quite well . For the past 3 days, I got consistent AHI readings between 8 and 10 . I will continue this procedure for another 4 days andd see how it goes....

(07-09-2018, 09:12 AM)tommyngo Wrote: _I am also wondering if there is a commercial device that measures the AHI ( i.e. independent of the CPAP machine ) .

There are a number different home sleep study machines that measure AHI.

The ResMed and Embletta devices have effort bands that go around your abdomen, and a nasal canula that measures flow, among other metrics.
The WatchPat goes on your finger measures intra-thoracic pressure, which it can extrapolate into obstructive and central apneas.

As far as I know, none of them are available to the general public other than as a physician prescribed test. The WatchPat costs something like $4,000, and uses sensors that have to be replaced each night.

It would be interesting if Autoset machines could have some extra data channels. And the Airsense 10 does. Unfortunately, the pulse ox channel on the Airsense requires $900 worth of accessories to use, so I don't think other tools like a nasal canula for detecting flow and AHI while sleeping without PAP seems like a tool they'd ever add to the machines. A body position channel would be nice, though, since I know many OSAs and mask leaks can depend on body position.

I don't understand why you are depriving yourself of therapy pressures you should be using to fully resolve AHI. Your low pressure AHI is not particularly alarming, but this is unnecessary and counter-productive. Raise your minimum pressure and enjoy some good sleep! Using a CPAP at sub-therapeutic pressures is proving nothing other than the fact you need higher pressure. This is not an untreated pressure or sleep test and has no medical benefit whatsoever.

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